My 1961 Alden Challenger, now on it's 3rd engine, has the original exhaust. Or, I should say, 'had'.
These old double wall pipe exhausts are considered dangerous because there is no way to tell when the inner pipe will fail thus allow the cooling raw water in the outer jacket, to flow back into the engine on shut down. Catastrophic failure. After haul out, I began cutting the old exhaust out of the boat.
After my first cut with a new Sawzall blade, my first thought was, "What have I done?" It turns out the pipe was very thick, very solid copper and some bronze. Further dissection I found beyond the high loop where the raw water exits and enters a 1961 cast iron Maxim Silencer muffler (very effective), everything was solid. It doesn't matter now. I've got to install a modern water lift muffler system.
I've researched and researched. A particularly helpful article is one from Good Old Boat that's online.
Good Old Boat - Cool and Quiet and trouble-free article
At this point: I've ordered a Centrex waterlift with a larger volume and a water injection elbow.
This is a shot from just forward of the steering quadrant in my engine compartment. The blue horizontal line is roughly the water line. I plan to mount the muffler (blue square) after of the engine and alongside the transmission. The thick blue line is roughly where I plan to run the 2 3/8" exhaust hose.
Here's a sketch from the side: The plan is to install a pipe riser off the exhaust manifold to raise the water injection elbow, and to install a vented loop(just below the cockpit sole or possibly higher if I can fit it), on the raw water line.
It would be nice to run the exhaust hose up into a cockpit locker - which could put it at it's highest point - but I don't want the hose in the access area(my last boat was that way).
I think this should work but any ideas would be appreciated. Thanks!